Construction and Testing of Coin Cells of Lithium Ion Batteries

Rechargeable lithium ion batteries have wide applications in electronics, where customers always demand more capacity and longer lifetime. Lithium ion batteries have also been considered to be used in electric and hybrid vehicles¹ or even electrical grid stabilization systems². All these applications simulate a dramatic increase in the research and development of battery materials^3-7, including new materials^3,8, doping⁹, nanostructuring^10-13, coatings or surface modifications^14-17 and novel binders¹⁸. Consequently, an increasing number of physicists, chemists and materials scientists have recently ventured into this area. Coin cells are widely used in research laboratories to test new battery materials; even for the research and development that target large-scale and high-power applications, small coin cells are often used to test the capacities and rate capabilities of new materials in the initial stage. In 2010, we started a National Science Foundation (NSF) sponsored research project to investigate the surface adsorption and disordering in battery materials (grant no. DMR-1006515). In the initial stage of this project, we have struggled to learn the techniques of assembling and testing coin cells, which cannot be achieved without numerous help of other researchers in other universities (through frequent calls, email exchanges and two site visits). Thus, we feel that it is beneficial to document, by both text and video, a protocol of assembling and testing a coin cell, which will help other new researchers in this field. This effort represents the "Broader Impact" activities of our NSF project, and it will also help to educate and inspire students.In this video article, we document a protocol to assemble a CR2032 coin cell with a LiCoO₂ working electrode, a Li counter electrode, and (the mostly commonly used) polyvinylidene fluoride (PVDF) binder. To ensure new learners to readily repeat the protocol, we keep the protocol as specific and explicit as we can. However, it is important to note that in specific research and development work, many parameters adopted here can be varied. First, one can make coin cells of different sizes and test the working electrode against a counter electrode other than Li. Second, the amounts of C black and binder added into the working electrodes are often varied to suit the particular purpose of research; for example, large amounts of C black or even inert powder were added to the working electrode to test the "intrinsic" performance of cathode materials¹⁴. Third, better binders (other than PVDF) have also developed and used¹⁸. Finally, other types of electrolytes (instead of LiPF₆) can also be used; in fact, certain high-voltage electrode materials will require the uses of special electrolytes⁷.     

The effect of clomiphene citrate and human chorionic gonadotropin on the expression of CatSper1, CatSper2, LHCGR,and SF1 genes,as well as the structural changes in testicular tissue of adult rats

The purpose of this study was to investigate the effect of clomiphene citrate and human chorionic gonadotropin (HCG) on the structural changes, as well as the evaluation of the expression of cation channel sperm‐associated protein 1 (CatSper1), cation channel sperm‐associated protein 2 (CatSper2), luteinizing hormone/choriogonadotropin receptor (LHCGR), and steroidogenic factor 1 (SF1) genes in testicular tissue of rats. All rats divided into five groups as follows; G1 as the control group that received normal saline, G2 received olive oil, G3 received 100 IU/kg HCG, G4 received 5 mg/kg clomiphene citrate, and G5 received 5 mg/kg clomiphene citrate and 100 IU/kg HCG. At the end of the experiment period, Day 56, blood samples were taken and the serum was isolated. Then, histomorphometric analysis, hormonal assess, and real‐time polymerase chain reaction to measure the expression of CatSper1, CatSper2, LHCGR, and SF1 genes were performed. The results showed that the concentrations of testosterone, follicle‐stimulating hormone, and luteinizing hormone were decreased in the G4 group, whereas these parameters were increased in the G3 group. A comparison of the sperm quality indicated a significant reduction in the quality of sperm cells in the G4 group compared with other groups. The quality of sperm was significantly enhanced in the G3 and G5 groups in comparison with the G1 group. Also, our findings demonstrated that the expression of CatSper1, CatSper2, LHCGR, and SF1 genes were significantly elevated in the G3 group when compared with other experimental groups. According to the obtained results, it seems that clomiphene citrate reduces the process of spermatogenesis and the detrimental impacts of this compound would be neutralized by the administration of HCG.     

Non-carcinogenic risk assessment to human health due to intake of fluoride in the groundwater in rural areas of Gonabad and Bajestan,Iran: A case study

In this study, a field research regarding groundwater contamination with fluoride and its related health risks to human health was carried out in 39 rural areas of Gonabad and Bajestan, Iran, in 2017. The results indicated that fluoride levels in two rural areas exceeded the WHO guideline. A total of 55% and 4.7% of the studied rural areas in Gonabad and Bajestan, respectively, had fluoride levels below the minimum recommended value of WHO for fluoride (0.5 mg/L). In this article, chronic non-cancer risks to three different groups of people, adults, children, and infants, for exposure to the fluoride were assessed. Health risk index values for fluoride contamination for 44% and 90% of children and infants in rural areas of Gonabad and Bajestan, respectively, were more than unity (>1), which clearly reveals that these age groups at the studied areas are at the chronic health risk due to the intake of fluoride-containing water. The order of fluoride contribution to non-carcinogenic health risk among the studied age groups was infants > children > adults. Therefore, from a public health viewpoint, it would be prudent and important that risk reduction measures be implemented to diminish the total body burden of fluoride in residents.     

Familial Cases of Trichophyton benhamiae Infection Transmitted from a Guinea Pig in Iran

Mycopathologia - Trichophyton benhamiae is a zoophilic dermatophyte mainly transmitted to humans from guinea pigs. This zoophilic species can also cause dermatophytosis as reported by human contact...     

Identification and molecular characterization of the cDNA encoding Cucumis melo allergen,Cuc m 3, a plant pathogenesis-related protein

Background:

Melon (Cucumis melo) allergy is one of the most common food allergies, characterized by oral allergy syndrome. To date, two allergen molecules, Cuc m 1 and Cuc m 2, have been fully characterized in melon pulp, but there are few reports about the molecular characteristics of Cuc m 3.

Methods:

The Cuc m 3 cDNA has been characterized by rapid amplification of cDNA ends (RACE), which revealed a 456 base-pair (bp) fragment encoding a 151-amino acid polypeptide with a predicted molecular mass of 16.97 kDa, and identified 79 and 178 bp untranslated sequences at the 5′ and 3´ ends, respectively.

Results:

In silico analysis showed strong similarities between Cuc m 3 and other plant pathogen-related protein 1s from cucumber, grape, bell pepper, and tomato.

Conclusion:

Here we report the identification and characterization of the Cuc m 3 cDNA, which will be utilized for further analyses of structural and allergenic features of this allergen. Key Words: Melon, allergen, Cuc m 3, plant pathogenesis-related protein 1     

Effect of tumor shape,size, and tissue transport properties on drug delivery to solid tumors

Background

The computational methods provide condition for investigation related to the process of drug delivery, such as convection and diffusion of drug in extracellular matrices, drug extravasation from microvessels or to lymphatic vessels. The information of this process clarifies the mechanisms of drug delivery from the injection site to absorption by a solid tumor. In this study, an advanced numerical method is used to solve fluid flow and solute transport equations simultaneously to investigate the effect of tumor shape and size on drug delivery to solid tumor.

Methods

The advanced mathematical model used in our previous work is further developed by adding solute transport equation to the governing equations. After applying appropriate boundary and initial conditions on tumor and surrounding tissue geometry, the element-based finite volume method is used for solving governing equations of drug delivery in solid tumor. Also, the effects of size and shape of tumor and some of tissue transport parameters such as effective pressure and hydraulic conductivity on interstitial fluid flow and drug delivery are investigated.

Results

Sensitivity analysis shows that drug delivery in prolate shape is significantly better than other tumor shapes. Considering size effect, increasing tumor size decreases drug concentration in interstitial fluid. This study shows that dependency of drug concentration in interstitial fluid to osmotic and intravascular pressure is negligible.

Conclusions

This study shows that among diffusion and convection mechanisms of drug transport, diffusion is dominant in most different tumor shapes and sizes. In tumors in which the convection has considerable effect, the drug concentration is larger than that of other tumors at the same time post injection.

     

Targeting Prolyl Endopeptidase with Valproic Acid as a Potential Modulator of Neutrophilic Inflammation

A novel neutrophil chemoattractant derived from collagen, proline-glycine-proline (PGP), has been recently characterized in chronic obstructive pulmonary disease (COPD). This peptide is derived via the proteolytic activity of matrix metalloproteases (MMP''s)-8/9 and PE, enzymes produced by neutrophils and present in COPD serum and sputum. Valproic acid (VPA) is an inhibitor of PE and could possibly have an effect on the severity of chronic inflammation. Here the interaction site of VPA to PE and the resulting effect on the secondary structure of PE is investigated. Also, the potential inhibition of PGP-generation by VPA was examined in vitro and in vivo to improve our understanding of the biological role of VPA. UV- visible, fluorescence spectroscopy, CD and NMR were used to determine kinetic information and structural interactions between VPA and PE. In vitro, PGP generation was significantly inhibited by VPA. In vivo, VPA significantly reduced cigarette-smoke induced neutrophil influx. Investigating the molecular interaction between VPA and PE showed that VPA modified the secondary structure of PE, making substrate binding at the catalytic side of PE impossible. Revealing the molecular interaction VPA to PE may lead to a better understanding of the involvement of PE and PGP in inflammatory conditions. In addition, the model of VPA interaction with PE suggests that PE inhibitors have a great potential to serve as therapeutics in inflammatory disorders.     

Study on the bioactivity of steviol and isosteviol in stevia (Stevia rebaudiana Bertoni)

Steviol and isosteviol are diterpene metabolites that are produced from a shared biosynthesis pathway with gibberellins in stevia leaves. These compounds share a chemically similar structure with gibberellins. An experiment was conducted to find the bioactivity properties of steviol and isosteviol in stevia. During vegetative growth, external solutions of steviol and isosteviol (1.6 × 10^?5 and 1 × 10^?5 M, respectively) were sprayed on stevia shoots and then the stevia growth and metabolites were assessed. The results showed that the stevia leaf growth was reduced by external application of steviol. The leaf growth was not affected by external isosteviol while the stevia height and stem dry weight significantly increased. The antioxidant capacity and steviol glycosides content were increased by external steviol. Our results implicated that the isosteviol bioactivity is similar to that of gibberellin hormone. On the other hand, steviol induces the antioxidant system and stimulates the steviol glycosides biosynthesis in stevia leaves.     

cis-Dioxo-molybdenum(VI)-oxazoline complex catalyzed epoxidation of olefins by tert-butyl hydrogen peroxide

A new efficient catalytic system was investigated for the epoxidation of various olefins by cis-dioxo-bis[2-(2′-hydroxyphenyl)-oxazolinato]molybdenum(VI), cis-[MoO₂(phox)₂], and TBHP as oxidizing agent. Using this system as catalyst for the oxidation of aliphatic substrates at 80 °C gives the epoxide as the sole product with yields up to 100% and turnover frequency up to 5000 h⁻¹. The efficiency of the catalyst is strongly influenced by the nature of solvent, reaction time and temperature, and a significant increase in the epoxide yields is observed in higher temperatures and longer reaction times.     

Evaluation the Properties of Polycaprolactone/Fluorapatite Nano-biocomposite

In this study,nano-biocomposites of polycaprolactone(PCL)as the matrix and different amounts of nanofluorapatite(nFA)(0,10,20 and 30 wt.％)as the reinforcement w...